1. No Rarity Symbol Pikachu Illustrator (1998): This card was awarded as a prize in a Japanese illustration contest and is incredibly rare. Only 39 are believed to exist, making it arguably the rarest Pokémon card.
2. No Rarity Symbol Trophy Pikachu (1998): Similar to the Illustrator card, the Trophy Pikachu was awarded as a prize in a Japanese Pokémon card tournament. Its rarity is estimated to be around 12 known copies, making it extremely valuable.
3. Pikachu Trainer Number Card (1998): These cards were awarded as a prize to the top 12 players at the 1998 Pokémon World Championships in Japan. There were 12 unique cards featuring different trainer numbers and they're highly sought after by collectors.
Keep in mind that there are other incredibly rare cards out there, and the value of a card can fluctuate based on market trends and collector demand.